Process of decolorizing oil



F. w. MANNING- PRocEss oF DEcoLoRIzING oIL Aug. 12

`Filed March 13 1920 1 Sm, M QN Nm. M A 5 s s y as 5 w um ,f i .d 7 M zm M W Wm www, 4, n. y v M w y s l a, l. n um o 3 W 9 w n colorizinPatented Aug. 12, 1924.

UMTEDA STATES PATENT OFFICE.-

'FRED W. MANNING, or CHICAGO, ILLrNoIs, AssIeNoR To MANN-ING BEFININGEQUIPMENT CORPORATION, A ooRroRA'rIoN oF DELAWARE l PROCESS 0FDECOLRIZING OIL.

Applicationled March 13, 1920. Serial No 365,537.

To all whom t ma concern:

Be it known that FRED W. MANNING, a subject of the King of GreatBritain, and a resident of Chicago, county of Cook, and State ofIllinois, have invented certain new and useful Improvements in a Processof De- Oil, of which the following is a specification. i

This invention relates to filtering and particularly to the process offiltering. pe-

y troleum oil products, shale oils or other mineral oils throughfullersearth or other filtering medium for the purpose of decolorizingor otherwise purifying them. More specificall it relates to an improvedmethod of first ringing the oil into contact with a limited quantity ofa decolorizing medium and then quickly separating .it

therefrom so that great gains in efficiency,

speed and plant capacityT are secured over the methods hitherto used. ,A

It is well known to those versed .in the art that the method offiltering oils now generally used and particularly with mineral oils,through fullers earth is both cumbersome and inefficient. `In fact, it'is only the outgrowth of the first crude attempts to improve the colorand nature of oil products by filteration. The usual practice wherepetroleum products such as lubricating oils, cylinder stocks, etc., arefiltered, is to charge vfrom 20 to 50 tons of coarse fullers earth intovertical filters or percolators, these being guilt of light steel plateas practice has proven that high pressures are not applicable to thismethod of filtering. Commonpractice is to feed the o'l into the top ofthe percolators and filtered by gravity at atmospheric pressure,although, some refineries filter under a low pressure of five to'fifteenpounds. The oil remaining in the earth is then driven out to some extentby air ressure, is then more thoroughly taken out y a naphtha wash andthe naphtha is then steamed out.

There are serious objections to the present method of filtration, abovedescribed, among which are, the slow rate of filtration and ther greatlength of time required for operations other than those producingfiltered oil, due to the great depth of fullers earth usually varyingfrom 15 to 2O feet in the vertical type filter; the tendency to channelallowing unfiltered stock-to get into the ltrate; the lowyield offiltrate per pound of clay due to the tendency of the unfiltered stockto pass down thru the filter between the coarse grains instead of thruthe grains of fullers earth; fractional filtration which means that fora certain uantity of unfiltered stock charged tothe lter, only a limitedamount of a given grade of filtrate can be taken oli',

the'stream of oil from the filter becoming more and more like theoriginal stock charged to the filter as filtration proceeds, the spentearth being saturated at the end of the filtration period with oilalmost as impure as the original stock; and the impossibility. of usingthe fine mesh earth which occurs at the mills when grinding the coarsesizes and which loss is of serious importance 'to the mill owners as itamounts to about 15 per cent of the total amount mined and sold fortreating mineral oils.

I have discovered that much better resuits can be obtained by using avery fine grade of fullers earth, usually 60 mesh and finer linaccordance with my improved process instead of the coarse earth nowemployed.

oil to give a suspension which, because ofV the relatively smallproportion of earth, is easily pumped and handled. The decolorizingaction, because of the intimacy of contact of fine earth and oil, ispractically instantaneous, tain-ng place during the mixing. Any longcontinued action of the earth on the oil results in other changes thanthe sim le decolorization and purification' here desired; but nosubstantial time is here afforded for such changes. -When the mixture ismade, all the actions here desired are completed, and the mixture is atonce sepa-v rated; Vhigh pressure and a uickly actin .type of 'filteringapparatus bemg employe to hasten the separatiom The operation of myimproved processcan be best described in connection vwltharepresentation of suitable apparatus such as is shown in theaccompanying drawing, in

which Fig. 1 is a diagrammatic elevation of a specific assembly ofapparatus suitable for carrying out the improved process.

Fi 2 isl an enlar ed fragmentary sectiona detail of the the material isfed to the filter.

The apparatus, which for the sake of clearness is shown diagrammaticallywithout strict regard lto proportion of various parts, comprises amixing tank 1 equipped with heating coils 2 or suitab-le means forheating its contents and with a mechanical mixing means, as for example,rotary paddles 3, a pump 4 and suitable pipes 5, 6 and 7 connecting themixing tank 1 with a pressure filter 8 which mav be of the typedescribed in mv copending application filed September 18, 1919, SerialNo. 324,507.` As there shown, the drum is provided with an annular wallof perforated, slotted. or reticulated metal within screen wall 51. On50 the separated fine earth banks up as indicated at 52. In the formshown, the filter comprises a cylindrical shell having annular tracks 9supported on four rollers 10 and equip-pcd with mechanism for rotatingthe drum, which mechanism may consist of a motor 11 operativelyconnected tothe rollers 10.

A stationaryyfitting 12 located 1n axial alinement with the filter 8 isconnected with one end of the filter by means of a pipe 13 and stuflingbox 14. Thel inlet pipe 15 which connects the pipe 7 with the interiorof the filter, extends through the fitting 12 and is provided withsuitable Stuiiing boxes 16 and 17 where it enters said fitting andconnects with the pipe 7. Saidy tube carries a pulley 18 whereby it mayvbe drivenby a belt 19. A spiral conveyor 2O having a lhollow shaft isconnected to and operated by the tube 15. As shown, this hollow shaftAis a continuation of tube 15. The interior of the conveyor shaftcommunicates with the interior of the filter through apertures 21.

. The outlet for the filtratel is indicated at 22.

After the filtering medium such as fullers earth Ahas served its purposeand becomes charged with coloring matter, it is discharged from thefilter by means of the conveyor 20and -a pipe 23 which is connected withthe fitting-12 and controlled 'b a gate valve The oil that is to be rened, as for example, cylinder stock, is conducted to the mixingtank 1 bya valve controlled pipe' tting through which whereby the naphtha whichis used for a final wash in recovering oil from the filtering medium,can be conducted back t0 the pump and used for a first wash for thenext` batch. The pipe 7 has connected directly thereto, pipes 31 and 32.which are respectively iconnected to sources of air and steam underpressure.

In carrying out the improved method of refining oil, the unrefined oilis discharged by the pipe 25 into the mixing tank 1, and if this oil isheavy and thick as for example in the case of cylinder stock, the tankmay be heated to render the oil more fluid. A suitable quantity offullers earth is also discharged into the tank from the pipe 26, and theAearth and oil are thoroughly mixed by means of the power driven paddle3. This earth is of the fine grades now not used and discarded; materialof a fineness of 60 to 100 mesh and finer. iVith heavy oils ofv highviscosity, say, 150 to 300 at the filtration 4 temperature, earthbetween 60 and 100 mesh is suitable but for lighter oils whose viscosityis, or can be, reduced below 150, still finer mesh, say 100 mesh orfiner, is advisable. pump 4 is operated for forcing the mixed oil andearth into the filter where it passes out of the apertures 21 in thehollow conveyor shaft, overfiows the conveyor trough 34 and isdistributed over the filtering surfaces whereby the earth is separatedVfrom the oil. Instead of heating thick oil to thin it, it may bethinned with a little naphtha.

As stated complete decolorization takes place almost immediately whenthe `earth and oil come together in the mixing tank, due to the finenessof the fullers earth, and filtration is advantageously effectedimmediately thereafter at a great speed under highl pressure in thistype of rotai filter. The rotation of the filter uniform y distributesthe quickly settling earth over the filtering surfaces and avoids theeffects4 of channeling which occur in the usual percolating filters.vThe rotary filter is advantageous in carrying out the herein describedprocess because by its use the earth is distributed over the annularlfiltering surface'in a comparatively thin compact layer and at the sametime almost completely fills the filter, and this facilitates' the otheroperations Such as airing,'washing, and steaming and permits theseoperations also to take place at great speed under pressure. It isnotdesirable to have earth and oil remain in contact any longer than isabsolutely necessary. Fractional filtration is completely avoidedbecause decolorization takes place in the mixing tank where there is aneven distribution' of earth throughout the .o1l. Because of this fact,the oil which is held up in the earth during the filtering process 1sequal in quality to the filtered oil and may The valve 33 is thenopened, and the resulting from the first wash is added to the ,be addedto a aaaA being aken out of the earth by air pressure and naphtha wash.There is little of this retained 011 because of the lineness of theearth and the compactness of the layer. And Vwhat little there is can bereadily and quickly displaced by a naphtha wash without much dilutionbythe naphtha. Moreover any quantity of oil of any required color may beproduced by simple regulation of the quantities and proportions of theoil and earth in the mixing tank.

When the free spaces in the filter have become filled with earth, thefiltering operation is discontinued 'by stop-ping the pump 4 and closingthe valve 35. The residue of oil held up in the clay is removed by airunder pressure from the line 31, followed by successive washes ofnaphtha, usually two. This washing is done methodically. The naphthadfor the first fwash is a second wash from a prior operation and isobtained from the pipe and is forced through the filter by means of thepum 4. The second or final wash is fresh naplitha drawn from the pipe27. The mixture of oil and naphtha filtered oil and conveyed into asuitable tank not shown. The naphtha is then separated from the oil bydistillation. The naphtha which is used in the final wash, having but a'small charge of oil, is .sent to a separate tank communicating with thep-ipe 3.0 and is used as the lirst wash in the next cycle of operations.

After the washing operations have been completed and the naphtha hasbeen steamed out., the earth in the filter is left in the form of a dryIpowder and is discharged from the lter by means of a conveyor and pipe23.

This invention is not limited to any specific form of apparatus butresides 1n the described process steps, which may be carried out by avariety of apparatus.

By h drocarbon oils I refer to those 0btained om mineral sources.

I claim:

1. The process for improving hydrocarbon oils by quickly mixing with'them fine fullers earth, then quickly ilterin earth under heavypressure and `dlsplacing residual oil by naphtha introduced underpressure.

2. The process of improving hydrocarbon oils -Which consists in `firstquickly mixing the oil with fine fullers earth, then passing the mixturethrough a pressure filter to separate the oil and earth and then washingthe residue of oil from the earth by means of a solvent of hydrocarbonoil.

3. Thev process of purifying hydrocarbon oils which consists of quicklymixing powdered fullers earth with the oil, then quickly filtering outthe earth at high pressure, passing air lthrough the earth to blow outresidual oil, then washing the earth with naphtha, and finally passinfrsteam through the earth to remove the napltha.

4. The process of purifying hydrocarbon oils which consists of quicklymlxing powdered fullers earth with the oil, then quickly filtering outlthe earth at high pressure, and then subjecting the earth to successiveWashes. of naphtlia, the liquid resuiting from a second washing in aprior operation being used as a irst washing agent.

5.`A process of purifying hydrocarbonoils in which the oil is firstmixed with a line lpurifying agent and the resulting mixture passedthrough a pressure filter to separate the oil and agent, the steps, incombination, of building up upon a rotatable c lindrical lter element acake having on y its outer surface in contact therewith and separatingthe residual oil from the agentlby contacting it with a non-aqueouswashmg medium.

' Signed at Chicago this 5th day of March, 1920.

FREDA W. MANNING.

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